230 SCALPELLUM VULGARE, 



fifteen segments in the shorter ramus. Third pair, with 

 the two rami equal in thickness, and with the segments 

 differing very little from those of the posterior cirri, 

 excepting that the serrated spines in the external lateral 

 rows are rather larger. The fourth pair is remarkable by 

 having, on the inner side of the upper edge of each seg- 

 ment, a little tuft of minute smooth spines, flattened, and 

 a little enlarged near their ends, so as to be spear-shaped ; 

 I could not see these singular spines on the other cirri. 

 The lower segments of the pedicels of all the cirri, except- 

 ing the sixth pair, are remarkable from having their inner 

 edges, in the middle, produced into a considerable, abrupt, 

 rounded projection, irregularly covered with spines. 



Caudal Appendages, (PL X, fig. 21,) very small, 

 flattened, of nearly the same width throughout ; in a 

 medium-sized specimen, only -j-J-o-th of an inch in length; 

 each bears from ten to twenty small bristles placed dis- 

 tantly from each other, of which those on the rounded 

 apex are the longest. 



Generative System. — The penis is remarkably acumi- 

 nated ; the vesicular seminales are unusually small, and 

 enter only for a short distance into the prosoma; the 

 testes are large. The ovarian tubes are of large diameter ; 

 the ova are nearly spherical and large, namely, -^^-o-ths of 

 an inch in diameter ; they are not numerous, and lie in 

 single layers in the two lamellae. The ovigerous fraena 

 are well developed, and lie under the scuta; one I 

 measured was xf^ths of an inch in length and T tb-ths in 

 width ; the margin is obliquely truncated and slightly 

 sinuous. This species breeds late in the autumn, and 

 even in mid- winter ; I have examined a specimen from 

 Cornwall with ova containing larvae, taken on the 26th 

 of October; again, in another specimen from Belfast, 

 sent to me by Mr. Thompson, taken in January, there 

 were ova in the lamellae, and therefore no doubt impreg- 

 nated; and on February the 12th I received from Mr. Peach, 

 from Cornwall, specimens so very young that they must 

 have become attached during the first days of the month. 



